Lecture #4 and #5: Circulation And The Heart

Question 1

Fish blood circulation

Answer 1

Single loop:
Fish heart has 2 chambers

Gills —> artery —> heart —> tissues of the body —-> artery —-> back to gills

Question 2

Mammal circulation

Answer 2

Double loop
- Mammal heart has 4 chambers
Difficulty returning blood through veins to heart
1. muscle movement to squeeze veins
• low muscle movement = poor circulation
2. One way veins

Question 3

Cardinc cycle

Answer 3

Diastole and systole

Question 4

Diastole

Answer 4

Relaxation
- atrium completely fills with blood
- ventricle partly fills with blood

Question 5

Systole

Answer 5

Contraction
- atrium contracts first, ventricle completely fills with blood
~ 1/10th sec delay ~
- ventricles contracts while valves (bicuspid and tricuspid) between atria and ventricle closes
- valves between ventricles and arteries open, blood leaves heart
- valves between ventricles and arteries close as ventricle relaxes

Question 6

Where is the natural pacemaker located?

Answer 6

right atrium

Question 7

AV electrical node

Answer 7

electrical activity is focused on AV node before passing through ventricle

Question 8

Heart conditions

Answer 8

Angina
Cardiac arrest
Heart murmur
Heart attack
Fibulation

Question 9

Angina

Answer 9

Pain from blockage in coronary artery

Question 10

Cardiac arrest

Answer 10

Heart stops beating from electrical problem

Question 11

Heart murmur

Answer 11

Incomplete closure of valve
- makes heart work overtime

Question 12

Heart attack

Answer 12

Blood flow to the heart is blocked
- can cause cardiac arrest

Question 13

Fibulation

Answer 13

Fluttering of the heart due to electrical problems

Question 14

Blood pressure

Answer 14

Force of blood against sidewalls of vessels
- amount of fluid goes up = cardiac output (pressure goes up)
- Friction goes up = pressure goes up
- Cross - sectional area = pressure goes down
•higher b.p at arterial end of capillary
• Lower b.p at venous end

Question 15

Specific blood pressure

Answer 15

Taken in a specific area (ex: arm)
Systolic/diastolic
- 120/70 is average b.p
- 120 = systolic
- 70 = diastolic

Question 16

What area of the heart has the largest cross-sectional area?

Answer 16

Capillaries
- low pressure

Question 17

What causes high blood pressure (hypertension)?

Answer 17

• Salt intake
• Chronic stress
• Genetics
• Age (hardening of the arteries as you get older)
• Lack of exercise
• Fat intake (causes friction + reduces cross sectional area)

Question 18

How does respiration work in fish?

Answer 18

Water in the and mouth passes over gills

Question 19

How does the parallel current work (hypothetical)?

Answer 19

Water goes in and out in one direction, Blood goes in and out in the same direction
- 50% efficiency in oxygen exchange
- can’t take in oxygen after 50%

Question 20

How does the counter current work?

Answer 20

Water goes in and out one direction, Blood goes in and out in the opposite direction
- 85% efficiency
- more O2 can be taken in after 85%
- Fish use this system

Question 21

What do nasal passages do?

Answer 21

1. Moisten air
2. Warms air
3. Filters air (nasal hair + mucus)
4. Antimicrobials in mucus of nose

Question 22

Trachea (wind pipe)

Answer 22

• cilated epithelium
• tracial rings (cartilage support)

Question 23

Alveoli (Alveolus)

Answer 23

• each has a capillary network
• moist
• thin epithelium (simple squamos)

Question 24

Breathing cycle

Answer 24

Inhalation
- ribs out, diaphram down
- lung volume increase
- pressure goes down (negative pressure)
- Air goes in
Exhalation
- opposite of inhalation
- ribs in, diaphram up, lung volume decreases, pressure goes up, air out

Question 25

Elastic recoil

Answer 25

makes it easier to decrease lung volume and increase pressure

Question 26

During gestation

Answer 26

Humans - embryo implates into uterin wall ~ 5 days
- placenta fully formed by 1 month
Respiatory system
- last to mature ~ 8 months
At birth - lungs take over
- uses lungs for the first time

Question 27

Fetal hemoglobin

Answer 27

Higher efficiency for O2 than maternal hemoglobin
- ensures O2 crosses placenta

Question 28

Lymphatic system

Answer 28

One way flow towards circulatory system
1. Immune response - Body’s defense (lymph node)
2. Return excess fluid to circulatory system
3. Returns proteins that leak out to the circulatory system
4. Capillary - like vessels called lacteals that pick up digested lipids

Question 29

Components of blood

Answer 29

Red blood cells - iron
White blood cells
Platlets
Plasma - fluid
Gases (O2, CO2)
Glucose (sugar)
Proteins
Hormones - signals
Salts